setTimeout("start_slideshow()", 1000);

function start_slideshow() {
    var end_frame = $$('#slide-images li').length - 1;
    setTimeout(switch_slides(0,0,end_frame, 7000), 4000);
}

function switch_slides(frame, start_frame, end_frame, delay) {
    return (function() {
        Effect.Fade('slideshow' + frame);
        if (frame == end_frame) { frame = start_frame; } else { frame = frame + 1; }
        setTimeout("Effect.Appear('slideshow" + frame + "');", 850);
        setTimeout(switch_slides(frame, start_frame, end_frame, delay), delay + 850);
    })
}